Device for laying out and setting up molding-cutters.



No; 866,205. PATENTED SEPT. 17," 1907. 0. LEE.

.DEVICE FOR LAYING OUT AND SETTING UP MOLDING GUTTERS.

AYYLIOATIOK mm: 1.9, 1906.

2 SHEETS-SHEET 1.

. witnesses I Inventor: M W, Jaw/4&0 6Q? V W PATENT-ED SEPT. 17,1907.

0. LEE. DEVICE FOR LAYING OUT AND SETTING UPMOLDING GUTTERS.

7 APPLICATION FILED JAILQ, 1906.

2 SHEETS-SHEET 2.

[n Uentor':

with eases u RS cm, WASHINGFON, o. c.

UNITED STATES CHARLES LEE, OF CAMBRIDGE, MASSACHUSETTS.

DEVICE FOR LAYING OUT AND SETTING UP MOLDING-CUTTERS.

Specification of Letters Patent.

I Patented Sept. 17, 1907.

Application filed January 9,1906- Serial No. 295,266-

To all whom it may concern:

Be it known that CHARLES LEE, a citizen of the United States, residingat Cambridge, in the county of Middlcsex and State of Massachusetts,have invented new and useful Improvements in Devices for Laying Out andSetting Up Molding-Cutters, of which the following is a specification.

This invention relates to a device forlaying out the irregular cuttingedges of cutters for molding machines, so that when the cutter is placedupon the rotary head of the molding machine and the machine operated themolding which is cut by the rotation of the cutterswill be of the exactshape of the design required to be reproduced.

invention.

If the cutters were attached to the rotary head in such a manner thatthe front faces thereof were located in a plane radial from the axis ofthe rotary cutter head, the shape of the cutting edge of the cutterwould evidently be a duplicate of the irregular curve which it isdesired to reproduce in the molding made on the machine, but in a largepart of the molding machines now in use the cutters are adjustablyfastened to a cutter head with the front faces of said cutters lying ina plane not radial from the axis of the cutter head, but lying in aplane parallel to, and at a short distance from, said axis. Thislocation and arrangement of the cutters makes it necessary to form thecutting edge of the cutter upon a different curve from that which it isdesired to reproduce in the completed molding as hereinafter fullydescribed, and it is for the purpose of enabling the workman toaccurately lay off a curve which shall include an allowance for thisdifference between the shape required as to the cutter edge from that tobe produced in the completed molding, that this device has beenproduced.

The difference or allowance which has to be made between the shape ofthe cutter edge and the curve which said cutter finally produces in thecompleted molding is due to what is technically known as the over-hangof the cutter.

The invention consists of a tool graduated as described in the followingspecification, and particularly as set forth in the claims thereof.

Referring to the drawings: Figure 1 is a plan view of a T-square, theblade of which is provided with two scales one of which is graduated inaccordance with my Fig. 2 is a diagram illustrating the manner of layingout the curve by which the cutting edge of the cutter is to be formed inaccordance with my invention. Fig. 3 is a transverse section, partly inelevation, of a cutter head with the cutters attached thereto, and Fig.4 is a front elevation of a cutter head with one cutter attachedthereto, and a diagram holder with a diagram attached thereto shown inconnection with said cutter head in position to test the accuracy of theshape of the cutting edge of said cutter, said diagram holder and cutterhead being broken away to save space in the drawings. Fig. 5 is adiagrammatic view.

Like numerals refer to like parts throughout the several views of thedrawings.

Referring to Figs. 2 and 3, the irregular curve a is the curve of themolding which is to be produced, that is, the shape in cross section ofthe curved face of said molding, while the curve b is the curve uponwhich the cutting edge of the cutter must be formed in order to producethe curve a in the finished molding. The reason for this difference ofthe over-hang of the cutter between the curves at and b will be apparentby reference to Fig. 3, in which 5, 5 are the cutters, 6 the cut-. terhead, and 7 the shaft to which said cutter head is fastened and bywhich, it, together with the cutters thereon is rotated. 8, 8 are clampbolts andS), 9 clamp nuts, by means of which the cutters 5 are firmlyclamped to the cutter head 6, thebolt 8 in each case extending through aslot 10 in its respective cutter.

It will be noted that the front face 11 of each of the cutters 5liesagainst the face 12 of the cutter block 6, and each of the faces 12 liein a plane which is not radial from the axis of the cutter head, but isparallel to said axis and located at a distance therefrom. Now referringto the cutter 5 in the upper portion of Fig. 3, and assuming that thepoint e of said cutter corresponds with the point e on the diagram, Fig.2, then if it is desired to form the cutting edge of the cutter 5 sothat in practical operation it will cut a melding of the shape indicatedby the irregular curve a, then the edge of the cutter must be formedupon the irregular curve indicated by the letter I). For instance,taking the point d, we find that instead of laying off along the frontface 11 of the cutter 5, the distance d, d Fig, 2, it will be necessaryto lay off the distance d, d along the front face 11 of the cutter 5 inorder to obtain an increase in distance from the axis of the cutter head6, or in other words a radial increase equal to the distance d"; d, andit .is the radial increase which is effective in producing an increasein the depth of cut.

By reference to Fig. 3 this will be clearly seen referring to the dottedlines on the left of the upper cutter 5, in which the distancec, dequals the distance d, d, Fig. 2, which distance is the extra depth ofcut desired in the formation of the molding whose contour is illustratedby the irregular curve a, but it will be clearly seen that this distancea, d or d, d laid off along the front face of the cutter 5 is too shortto obtain the desired result in radial distance or effective distance bythe amount d, 01 and this amount is the over-hang..

In Fig. l is illustrated a tool which embodies my invention, the sameconsisting of a T-square having a head 13 and a blade 14; the blade 14has two graduated scales thereon, namely, the scale 15 and the scale 16.The scale 15 may be any standard scale, while the scale 16 is theover-hang scale. The graduations of the scale 16 differ from those ofthe scale 15 by an amount sufficient to compensate for the. loss indistance from the axis of said cutter head of measurements laid off inthe plane of the front face 11 of the cutter 5 transversely of thecutter head (i as compared with the same measurement laid off radiallyfrom said axis. To illustrate, take the distance marked 1/2 on thestandard scale 15; to find the correct amount to lay off on the face 11of the cutter to obtain a corresponding radial cut in the completedmolding, the distance marked 1/2 on the over-hang scale should be laidoff on the face 11 transversely of the cutter head.

The practical operation of my improved device for laying out and settingup molding cutters is as follows: The workman has given him an irregularcurve such as a Fig. 2, and it is desired that he shall reproduce thiscurve in the form of molding. To do this he takes a piece of paper 17lays the curve a off on it as shown in Fig. 2 and then with the T-squaredraws the lines e, e, e, Fig. 2, at right angles to the base line 9,which base line is drawn parallel to the back face i of the molding andthrough the points a, c which are farthest removed from the back face'5. He then moves the T-square along until the standard scale gives himthe distance from the line g to any given point, such as, for instance,the point d and then moves the T-square along until the over-hang scaleis in line with the point (i when he marks on the paper the point (P,which corresponds in the over-hang scale to the point d which he hasjust measured on the standard scale. In this way he gets a series ofpoints from his over-hang scale for the irregular or over-hang curve band then draws the curve through these points as illustrated in Fig. 2.Having now obtained the over-hang or irregular curve upon which thecutting edge of the cutters must be formed in order to produce'in themolding the true curve a, he attaches the paper templet 17 to a templetholder 21 consisting of a flat strip 18 preferably of pine wood, a head19 fast thereto, and a strip of dark material such as black walnut orebony fast to the strip 18 and extending longitudinally thereof.

In attaching the templet 17 to the templet holder 21, the highest pointsof the molding c, c are placed in alinement with the upper edge of thedark strip 20, Fig. i, care being taken that the back face indicated byline i shall be kept parallel with the strip 20. The templet holder isthen held by the workman with the strip 20 in contact with one edge ofthe cutter head and extending longitudinally thereof and the cutterwhich is to be shaped is fastened to the cutter head as shown in Fig. 4,said cutter is then ground by the workman until the different points inthe cutting edge thereof coincide with the curve or irregular line b,and is then fastened to the cutter head; the molding is cut by themolding machine by the rotation of the cutter head 6 and the knives 5fast thereto in a manner well known to those skilled in this art.

It is evident that the scale 15 may be of any desired standard so longas the over-hang scale 16 is laid off to correspond with said standardand so that its graduations shall differ from the graduations of thestandard scale by an amount sufficient to equal said standardgraduations plus the over-hang of the cutter which is to be formed bythe method hereinbefore set forth.

The term overhang hereinbefore referred to may be understood byreference to the diagrammatic illustration Fig. 5, in which 11 is theface of the cutter 5 which rests upon the cutter block, said face notbeing radial to said block. The line 11 is extended along the line 0 I),while a c is the radial line of the cutter head. Assuming the'point c tobe the highest point in the curve which is to be cut from the moldingand that it is desired to cut at any point in the molding a depth equalto cd, if the face 11 of the cutter were coincident with the radial line0 c, then the distance 0 d would be added to the cutter edge at thepoints where it is desired to cut the extra depth 0 d, but as said face11 is not on the radial line 0 c, a distance 0 d must be added to theedge of the cutter in order to obtain in the molding a depth of cutequal to ed. The point d is obtained by laying off the distance 0 0which is equal to ad, on the radial line 0 0 then describing the are c dfrom the center a of the cutter head. The distance d d is the overhangcorresponding to the distance ad, which is the real distance desired tobe cut into the molding beyond the point a, which is the highest pointin the molding. The same is true if it is desired to cut a depth a a. Inthis case the overhang would be a b. If it is desired to cut a depth a abeyond the point a, then the overhang would be a b and by reference toFig. 2 the overhang of the cutter, as a whole, which is to cut a curveor are shape corresponding to the line a would be the space between saidline a and the line 1).

Having thus described my invention, what I claim and desire by LettersPatent to secure is:

1. A tool having two graduated scales thereon for laying out the cuttingedge of a cutter adapted to be fastened to the rotary cutter head of amolding machine, with the front face of said cutter in a plane parallelto and located at a distance from the axis of said cutter head, thedistance between any two graduation marks of one of said scalesdiifering from the distance between any two corresponding graduationmarks of the other of said scales relatively to the zero points of eachof said scales, respectively, by an amount suflicient to compensate forthe loss in distance from the axis of said cutter head, of a measurementlaid off in a plane transversely of said cutter head and outwardly froma given point, as compared with the same measurement laid oft from saidpoint radially from said axis.

2. A tool for laying out the cutting edge of a cutter for moldingmachines, said tool having two graduation scales thereon, the distancebetween any two graduation marks of one of said scales differing fromthe distance between any two corresponding graduation marks on the otherof said scales relatively to the zero points of each of said scales,respectively, by an amount equal to the corresponding overhang of thecutting edge of said critter.

3. A tool for laying out the cutting edge of a cutter for moldingmachines, said tool having two graduated scales thereon, the distancebetween any two graduation marks of one of said scales differing fromthe distance between any two corresponding graduation marks of the otherof said scales relatively to the zero point of said scales, respectively, by an amount sufiicient to compensate for the loss indistance from the axis of a rotary cutter head, to

which said cutter is fastened, with the front face of said cutter in aplane parallel to and located at a distance from the axis of said cutterhead, of a measurement laid 01f in a plane transversely of said cutterhead and outwardly from a given point as compared with the samemeasurement laid oif from said point radially from said axis.

4. A T-square for laying out the cutting edge of a cutter, having ablade with two graduated scales thereon, the distance between any twograduations of one of said 10 scales differing from the distance betweenany two corresponding graduations of the other of said scales relativelyto the zero point of said scales, respectively, by an amount equal tothe corresponding overhang of the cutting edge of said cutter.

In testimony whereof I have hereunto set my hand in 15 presence of twosubscribing witnesses.

CHARLES LEE.

Witnesses CHARLES S. Gooome, ANNIE J. DAILEY.

